PURPOSE: To make several temporary slides and to practice viewing them with a compound microscope.

MATERIALS NEEDED: Microscopes, slides, coverslips, droppers and water.

PROCEDURE ONE: Prepare a wet mount of two strands of human hair. (Taken from the closest source.)

1. Place two differently colored human hairs in an "X" shape on your slide.
2. Add one drop of water by placing it directly on top of the two hairs.
3. Install the coverslip with the technique demonstrated by your instructor.
4. View the slide under low power!
5. Sketch the hairs under low power here:

 

 

 

 

 

 

 

 

 

 

 

 

6. Switch to high power. Sketch the hairs under high power here:

ANALYSIS ONE:

1. How can the microscope be used to tell which hair is on top?
2. Are both hairs always in focus? What about when we change from low to high power?
3. What happened to the field of view when we switched to high power?
4. What happened to the brightness of the field of view when we changed from low to high power?
5. What happened to the distance between the objective and the stage when we switched power?

PROCEEDURE TWO: Prepare a wet mount of a typewritten letter.

1. Cut out a letter from the newspaper or a scrap of paper.
2. Place it on the slide
3. Add a drop of water to the slide by dropping it directly on the letter
4. Install a coverslip properly
5. View the slide under low power!
6. Sketch the letter under low power here:

 

 

 

 

 

 

 

 

 

 

 

 

 

7. Change to high power. Sketch the letter under high power here:

ANALYSIS TWO:

1. What happened to the letter when we changed from low power to high power!

1. Did the scope stay in focus during the change in power?
2. Microscope "A" has a 20X eyepiece and a 60X objective. Microscope "B" has a 10X eyepiece and a 40X objective.

• Which scope has the highest power?

• Which scope needs the most light?